How to Access a Oracle database using Oracle Sql Developer Tool

First you have to check the oracle connection details.

For this purpose use the Oracle Sql Developer Tool.

you can download it from this website.
http://www.oracle.com/technetwork/developer-tools/sql-developer/downloads/index.html

After downloading it to your local machine, unzip it and click on the "sqldeveloper" application to install it.

If Java is not installed on the machine

First you have to install the "supported" java JDK version to your machine.
otherwise it will ask the JDK path to install it.

Provide the Java bin folder path.
ex:
C:\Program Files\Java\jdk1.6.0_21\bin

If Java is already installed in the machine.

Click on the add connection
Then fill these required fields.

Connection Name:any
Username: Correct username
Password: Correct password

hostname: IP address or "localhost"
Port : Default Port "1521" or the Correct Port
SID : Default "xe" OR Service Name : any